The Glicko[0] rating system is different from Elo[1], and it's what Lichess and Chess.com use In Elo, the rating gain for one player equals the rating loss for

The Glicko[0] rating system is different from Elo[1], and it's what Lichess and Chess.com use In Elo, the rating gain for one player equals the rating loss for another, because each player's rating is the only independent variable. Glicko calculates a kind of 'certainty', aka 'rating deviation' which is based on the number of games played in some period of time. The idea is that the ratings of players who have not played in a while are more likely to be wrong. [0] https://en.wikipedia.org/wiki/Elo_rating_system https://en.wikipedia.org/wiki/Elo_rating_system [1] https://en.wikipedia.org/wiki/Glicko_rating_system https://en.wikipedia.org/wiki/Glicko_rating_system